A wide variety of customer devices connect to service provider networks to access resources and services provided by packet-based data networks, such as the Internet, enterprise intranets, content providers, and virtual private networks (VPNs). Each service provider network typically provides an extensive network infrastructure to provide packet-based data services to the customer devices. The service provider networks may comprise a wide area network (WAN). In some examples, each service provider network may comprise a single autonomous system (AS) within a WAN that includes multiple ASes. In other examples, each service provider network may comprise two or more ASes within the WAN.
The network infrastructure of a service provider network typically includes a vast collection of access nodes, aggregation nodes and high-speed edge routers interconnected by communication links. These network devices typically execute various protocols and exchange signaling messages to anchor and manage subscriber sessions and communication flows associated with customer devices. A software defined network (SDN) controller may be included in the network architecture to provide centralized control of the subscriber sessions and communication flows within the service provider network. In some cases, a SDN controller may provide centralized control over an entire WAN including multiple ASes. In this case, the SDN controller may be referred to as a SDN WAN controller or a SD-WAN controller.